G21 vs Sunlighten
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
G21
Easily plan and schedule your fitness classes directly from your mobile device. View class schedules, sign up for sessions, and access studio location information. Optimize your time and enjoy the convenience of managing your fitness activities on the go.
- View class schedules
- Sign up for classes
- Access studio location information
- Optimize time management
- Convenient mobile access
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Download the Gravity 21 App today to plan and schedule your classes! From this mobile App you can view class schedules, sign-up for classes, as well as view the studio’s location information. Optimize your time and maximize the convenience of signing up for classes from your device! Download this App today!
Sunlighten
Optimize your well-being with this app, designed to enhance your light therapy and sauna experiences. Create personalized wellness programs, track sessions in real-time, and control your devices remotely for a seamless health journey.
- Science-based wellness programs
- Personalized program creation
- Real-time session tracking
- Remote sauna control (Wi-Fi)
- Audio and lighting management
- Red light therapy panel programs
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Take your wellness journey to the next level with the Sunlighten app, designed to enhance your Sunlighten sauna and Sunlighten RED Light Therapy Panel experience and optimize your well-being. Stay in control, feel your best, and enjoy the full potential of Sunlighten products. Key Features: • Science-based wellness programs designed to help you reach your health goals. • Create your own personalized programs. • Real-time session tracking. • Schedule your sauna sessions to build a routine. • Remote sauna control for compatible connected saunas • Manage your sauna's audio and lighting settings. • Get the most of our your RED Light Therapy Panel with over 20 scientifically optimized programs and guidance from the leaders in light therapy. Owners of mPulse saunas and RED Light Therapy Panels can enjoy full access to all app features, while owners of Amplify, Signature, and Solo Rise models can take advantage of convenient audio control. Stay connected for exciting updates as we continue to enhance your Sunlighten experience!
Screenshots
Verdict
The clearest difference is rating: G21 at 3.7 against Sunlighten's 2.7. G21 also leads on update cadence (monthly vs every 4 months). Sunlighten's advantage is ads (none vs shown) and ratings volume (84 vs 3). On price, in-app purchases, device support and iOS requirement there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
G21 holds the better App Store score, 3.7 against 2.7. That said, the two scores are not equally well evidenced: Sunlighten has 84 ratings behind it against 3, so its average is the more settled of the two.
G21 ships an update monthly, Sunlighten every 4 months. The most recent releases landed on October 15, 2026 and October 30, 2026 respectively.
| Parameter | G21 | Sunlighten |
|---|---|---|
| Price | Free | Free |
| Rating | 3.7 (3 ratings) — better | 2.7 (84 ratings) |
| Positive reviews | — | 19.8% of reviews |
| Number of ratings | 3 | 84 — better |
| Update frequency | Monthly — better | Every 4 months |
| Ads | Yes | No — better |
| In-app purchases | No | No |
| Monetization | Ad-supported | Free — better |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 14.0 — better | 15.1 |
| Further details — not scored | ||
| Size | 152 MB | 53 MB |
| Age rating | 4+ | 17+ |
| Developer | Gravity 21 Fort Lauderdale, LLC | Sunlighten Inc |
Customer experience
G21
Sunlighten
Bugs and requests
G21
Not enough reviews yet to summarise bugs or requests.
Sunlighten
Reported bugs
4 issues- App fails to connect to sauna
- Scheduled programs not running as expected
- Inconsistent lighting controls
- Tablet frequently restarts or loses connection
Requested features
4 requests- Remote start and preheat capability
- Improved app stability and reliability
- Better integration between app and sauna
- More customization options
In-app purchases
G21
No in-app purchases
Sunlighten
No in-app purchases
